forgot return, of course:
> myTake :: IO [Int]
> myTake = do
> n <- rand 1 10
> return $ take n [1..10]
Lev Walkin wrote:
Iain Barnett wrote:
Hi,
I have a function, that produces a random number between two given
numbers
rand :: Int -> Int -> IO Int
rand low high = getStdRandom (randomR (low,high))
(Naively) I'd like to write something like
take (rand 1 10 ) [1..10]
and see [1,2,3,4] ... or anything but nasty type-error messages.
myTake :: IO [Int]
myTake = do
n <- rand 1 10
take n [1..10]
or
myTake = rand 1 10 >>= \n -> take n [1..10]
or
myTake = rand 1 10 >>= flip take [1..10]
I'm reading about 6 tutorials on monads simultaneously but still can't
crack this simple task, and won't pain you with all the permutations
of code I've already tried. It's a lot, and it ain't pretty.
Would anyone be able to break away from C/C++ vs Haskell to help? Just
a point in the right direction or a good doc to read, anything that
helps will be much appreciated.
Monad enlightenment happens after 7'th monad tutorial. Verified by me
and a few of my friends.
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